On November 18, 2016, in Robert Ito Farm v. The Moms on a Mission Hui, the US Court of Appeals for the Ninth Circuit held that a magistrate judge may rule on a motion to intervene without the consent of a prospective intervenor because the prospective intervenor is not a party under 28 U.S.C. § 636(c)(1) ( (9th Cir. Nov. 18, 2016)).

A group of industrial agriculture plaintiffs sued the County of Maui to challenge an environmental ordinance. The parties consented to have the case proceed before a magistrate judge. Two public interest citizens' groups, Shaka and Moms on a Mission Hui (MOM Hui), moved to intervene. The magistrate judge permitted Shaka to intervene but denied MOM Hui's motion. MOM Hui sought review of the denial in the district court, arguing that the magistrate judge lacked jurisdiction over a prospective intervenor that did not consent to proceed before the magistrate judge. The district court held that the magistrate judge had jurisdiction to decide the motion to intervene because the existing parties to the suit had consented to proceed before the magistrate judge. MOM Hui appealed.

The Ninth Circuit affirmed. Acknowledging that a magistrate judge only can preside over a case with the consent of all of the parties, the court held that prospective intervenors are not yet parties to the suit under 28 U.S.C. § 636(c)(1). The prospective intervenor's consent therefore is not required for the magistrate judge to decide the motion to intervene. The court further noted that the magistrate judge's intervention order became immediately appealable to the circuit court because the magistrate judge was effectively presiding as a district judge over the suit.